1. Field of the Invention
The present invention relates to a data erasing device used for erasing data recorded on a recording media.
2. Related Background Art
In a still video recording and reproducing device in which a data erasing device is used, a two inch diameter magnetic disk is employed as a magnetic media for recording photographed images. In such a device, two erasing methods of erasing data recorded on tracks of the magnetic disk have been proposed. The first method is known as "the individual erasing method", in which a magnetic head is moved to a designated track to erase data thereon, and the data on the designated track is erased in response to an operation signal, for example, an ON operation signal from an erasing instruction switch. The second method is known as "the lump erasing method", in which data on all tracks from the first track to the last track is erased in response to an operation signal from a specific switch.
In a still video recording and reproducing device, since photographed images are sequentially recorded from the first track positioned at the outermost track of the magnetic disk to the 50-th track as the innermost track thereof, or vice versa, the photographing place and the dates of the images recorded on the outer side tracks of the magnetic disk which are positioned far from a center of the magnetic disk usually differ from those of the images recorded on the inner side tracks which are positioned near the center of the magnetic disk. Accordingly, when unwanted photographed images recorded on the magnetic disk are to be erased, the image continuously recorded on a plurality of the outer side tracks or the inner side tracks of the magnetic disk are erased. The lump erasing method described above can not meet with this requirement. On the contrary, the individual erasing method also has a disadvantageous erasing operation because of a requirement of the individual designation of each track from which the image is to be erased, and requires a long operation time.
The drawbacks described above are, of course, inherent to other devices which handle erasable recording media, in addition to the still video recording and reproducing device described above.